1. Field of the Invention
The invention relates to a light emitting device. More particularly, the invention relates to a light emitting device having a heat dissipation casing.
2. Description of Related Art
With the rapid development of science and technology in recent years, the operation efficiency of the light emitting components has become higher and higher. Consequently, the heating power of various light emitting components has also ascended constantly. In order to prevent the light emitting components from temporary or permanent malfunction caused by the overheating of the light emitting components, providing sufficient heat dissipation efficacy will become very important. In order to effectively reduce the heat produced by the operation of the light emitting component, the heat dissipation component can be installed on the light emitting component whose temperature is easily raised, such that the heat produced by the operation of the light emitting component can be removed quickly.
In the conventional art, the heat dissipation method includes natural convection and forced convection. For example, if the heat produced by the light emitting component is removed by natural convection, the natural convection is generally accomplished by disposing the heat dissipation block on the light emitting component, disposing the heat dissipation block and the light emitting component in the heat dissipation casing, and the air inlet and air outlet of the heat dissipation casing are disposed on the side cover and upper cover respectively. However, in the design of disposing the air inlet and air outlet on the side cover and upper cover of the heat dissipation casing respectively, the air inlet is shielded because of the side splicing of the components. Therefore, the air inletting area is reduced, thereby the heat dissipation effect is reduced.